Intruder Alarm

Creatures don't untap during their controllers' untap steps.
Whenever a creature enters, untap all creatures.

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Absorb

Merrow Reejerey

Other Merfolk creatures you control get +1/+1.
Whenever you cast a Merfolk spell, you may tap or untap target permanent.

Panharmonicon

If an artifact or creature entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Merrow Commerce

At the beginning of your end step, untap all Merfolk you control.

Idyllic Tutor

Search your library for an enchantment card, reveal it, put it into your hand, then shuffle.

Consulate Crackdown

When Consulate Crackdown enters, exile all artifacts your opponents control until Consulate Crackdown leaves the battlefield.

Sygg, River Guide

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
{1}{W}: Target Merfolk you control gains protection from the color of your choice until end of turn.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.